Res ipsa loquitur is a latin term in tort law which means “[the evidence] speaks for itself.” The term applies to cases in which a defendant's negligence is apparent and inferable due to the nature of the injury or wrongdoing. The defendant is presumed negligent if they had sole control of whatever caused injury to the plaintiff. Res ipsa loquitor may apply even in circumstances where there is no direct evidence of negligence, except for the injury itself - which could not have occurred in the absence of negligence. For example, if a department store elevator falls with someone in it and the individual sues the store because they were injured, they do not need to prove the elevator malfunctioned and proximately caused their injury. It is self-evident that the elevator malfunctioned simply because it fell.
In the US, Res ipsa loquitor must generally satisfy 3 elements:
- the injury accident could not generally occur without someone's negligence
- the evidence in the case rules out the possibility that a third party or the plaintiff's own negligence could have caused the injury (in tort cases, the court may evaluate whether the plaintiff's actions played a role in causing or exacerbating their injury)
- the type of negligence alleged falls within the scope of duty which the defendant had to the plaintiff ('duty' is an individual's legal responsibility toward another to act in accordance with the law, or to adhere to a standard of care and not proceed in actions of negligence)
This common tort law doctrine infers negligence from the very nature of the injury, even in the absence of direct evidence of the defendant's behavior. There are generally no other plausible explanations for the injury that do not require the involvement of the defendant and their actions.
Res Ipsa Loquitor and Medical Malpractice
Because this doctrine applies when the allegedly negligent person has sole control of whatever may have caused the injury, healthcare providers are reflexively implicated in many types of injury which would not be possible without some form of misconduct on their part.
For example, if a physician leaves a scalpel inside of a patient's body and patient files a negligence claim seeking damages, the evidence, in this case, speaks for itself. It is not a more nuanced incidence of malpractice which would require experts to hash out the details, review the standard of care, and determine whether or not the healthcare provider deviated from the standard. Leaving an object in the patient's body is so overtly negligent that little is needed to prove the claim.
Res ipsa loquitor may apply to more nuanced cases as well. If, for example, a patient suffers nerve damage in the course of an operation with 10 surgeons and assistance, it may be unclear which physician is responsible, however under res ipsa loquitor it may be reasonably assumed that all physicians presented could be held liable for negligence simply due to their presence and role in the surgery.
The 'duty' aspect of res ipsa is readily articulated in medical malpractice cases. The 'standard of care' is a well-established totem of the patient-provider relationship. If the plaintiff is injured while the provider is rendering care, a violation of the standard of care may be alleged and subsequently scrutinized by the court system. Expert witness testimony is routinely used to establish the standard of care in a given medical field. Because of the complexity of medicine, the standard of care in gastroenterology, for example, is beyond the jury's knowledge and common experience so an expert is brought in to define it.
Expert testimony can be critical in rebutting res ipsa, by showing that the provider did not deviate from the standard of care or the care they rendered cannot be linked to the patient's injury. An expert may postulate that the plaintiff caused or contributed to their own injury or can infer that a third party was involved because the provider was not negligent based on the expert's understanding of the field. Rebutting res ipsa is a matter of rebutting the inference of negligence. The defense may be able to prove that the plaintiff could've taken reasonable care to prevent their injury, or the defense could show that the injury-causing event still could've taken place even if they'd taken reasonable care to prevent.